To ask the Scottish Executive what the estimated prison populations are (a) in total and (b) broken down by each category of prisoner for each of the years (i) 2003, (ii) 2008, (iii) 2013, (iv) 2018, (v) 2023 and (vi) 2028 or, if such information is not available, what information it can provide on this matter, at proportionate cost, to show the basis of planning for prison populations over the next 25 years.